1. Field of the Invention
The present invention relates to improvement of rim protectors in a pneumatic tire and, in more detail, the present invention relates to a pneumatic tire in which both high speed cornering performance and durability at bead portions are improved while maintaining the rim protection property.
2. Description of the Prior Art
In order to enhance the rim protection property, it is desirable to enlarge the size of the rim protectors, however, it is known that when the size of the rim protectors is enlarged, the rigidity of the rim protectors increases, thereby degrading high speed cornering performance due to interference with rim flanges at the time of high speed cornering.
Conventionally, in order to further improve high speed cornering performance while protecting a rim, a pneumatic tire formed with not less than one circumferential fine groove extending in a tire circumferential direction as a means to decrease the rigidity of the rim protectors (Japanese Patent Laid-Open Publication No. 2000-127717) has been provided. By forming these circumferential fine grooves (slits) on the rim protectors, the rigidity at the time of high speed cornering has been alleviated and improvement in said performance has been attempted.
However, when the circumferential fine grooves (slits) are formed on rim protectors, bead durability is degraded. In addition, forming the circumferential fine grooves (slits) keeping shapes of rim protectors enlarged causes the bead durability to degrade since load around bead portions is heavy.
The object of the present invention is to provide a pneumatic tire in which both high speed cornering performance and durability at bead portions are improved, while maintaining the rim protection property.